An integrated circuit or “chip” is generally installed on a system board which is ultimately installed in an end product. Commonly, an integrated circuit may be purchased for use in several (or many) different end products, often by different manufacturers. Consequently, a single chip design may have to be “fine tuned” or configured for optimal performance in a particular product. Moreover, due to tolerances and other inaccuracies in other components, it may even be important to be able to configure each chip when it is installed on the system board.
It will be appreciated that it may be impractical to use a separate chip design for similar applications. However, in the past, it has also been impractical to fine tune chips with external components. One known technique requires that specified pins of the chip be tied to external fixed components having values chosen to provide the necessary adjustment to a particular chip parameter. Another technique requires the use of external variable components which can be adjusted iteratively until the chip achieves the desired level of performance. In still another technique, internal fuses or the like in parallel with circuit trimming components are “blown” to attain target values.
Pin strapping techniques have been used, for example, to test chips. An otherwise unused pin is tied to an external ground or voltage to place a chip in either a test mode or a normal operating mode.
However, there remains a need for an integrated circuit having an inexpensive and efficient method for configuring internal parameters.